


Perfect Fit

by Kisuru



Category: Love Live! Sunshine!!
Genre: Breast Worship, F/F, First Time, Insecurity, Romance
Language: English
Status: Completed
Published: 2021-02-05
Updated: 2021-02-05
Packaged: 2021-03-15 06:09:12
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,764
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29184555
Author URL: https://archiveofourown.org/users/Kisuru/pseuds/Kisuru
Summary: Ruby knows having large breasts is a good thing, but she is still a little self-conscious about Dis seeing hers up close and personal. But there isn’t any reason to worry! Dia is not only ready to see her little sister’s breasts in their full glory, but she wants to feel them as close to her as possible.
Relationships: Kurosawa Dia/Kurosawa Ruby
Comments: 2
Kudos: 7
Collections: Chocolate Box - Round 6





	Perfect Fit

**Author's Note:**

  * For [rubylily](https://archiveofourown.org/users/rubylily/gifts).



Hand shaking, Ruby’s fingernails dug into the thin strap of her bra. Her mind raced, her body quickly heating up.  
  
“I… um, um, I just… really…” Ruby’s throat was dry. She was on the verge of showing her body off to Dia. Her shirt was already discarded on the floor and the pressure of her sister’s hungry gaze weighed down on her. “Onee-chan…!”  
  
“Take your time, Ruby, “ Dia reassured. She took a breath to control herself. “I can’t get enough of watching you.”   
  
“Really? You really can’t get enough of watching me? Even when… it will be the first time I’m showing myself to you... like this?” Ruby asked, quite pleased despite her inner worries flaring up. The latch was cold between her fingers, the metal urging her to snap it away.  
  
Dia’s breath quickened. She shook her head, her dark, lustrous hair fanning out around her, conviction clear. “Of course! Because it’s the first, I want to look at everything about you as much I can!”  
  
True to Dia’s hushed word, she was hyper-fixated on the slow movements of Ruby’s arms bent behind her body for the bra latch. With her position tilted forward, the widened curve of her breasts squashed together lured her in tenfold, and she couldn’t look away.  
  
The higher pitch Dia’s voice voice was not lost on Ruby. Her clumsy fingers danced on the latch even more. The latch threatened to fall, and the thrill of the chase filled Ruby’s heart. She said that with so much earnestnesss, but she still wanted to know then… she…  
  
Having Dia touch her breasts was one worry, but she had another worry.  
  
Could she go through with this!? Could she… could she, after kissing her sister passionately that night on her bed for who knows how long, unwrap herself now for Dia, offer her chest for her? When her chest was so large?  
  
Ruby slowly licked the corner of her swollen upper lip. She could still taste Dia and the opening and closing her lips. The sweet, delicious lingering heat from moments ago made her body ache.  
  
Standing several paces in front of Ruby, Dia’s state was no less aroused. Her eyes roved across her younger sister’s half-bare body. The bra didn’t fall fast enough! Time was cruel to her — cruel but oh, oh so irresistible. She planted her feet on the tatami mat, frustrated.  
  
Her dear Ruby had grown out so well in the right places. Her skin was so sleek, clean, and pure to her greedy eyes. But her plump chest was absolute heaven!  
  
The cool air prickled at her arms. For all the world to see in her bedroom, Dia’s exposed chest beat with excitement. She had to wait for her to take her time, stay vigilantly patient, not try to rush her in these precious seconds — she couldn’t take advantage of her insecurities.  
  
Ruby’s head fell. Her cheeks flushed, because she was unable to strip her own attention from the distracting show before her. Dia’s breasts were beautiful! Her breasts were smaller than hers after her recent growth spurt, both rounded globes perfectly a sight to behold.  
  
Her older sister… was so _hot_.  
  
The latch lightly clattered as she pressed on the metal and it dropped from her grip. The bra slipped from her shoulders. Crookedly, the bra fell to the ground near Dia’s discarded bra on the tatami. Their uniform shirts weren’t too far.  
  
“Pigii!” Ruby yelled.  
  
Instinctively, Ruby’s arms whipped up and covered her large chest. Her breasts squeezed tightly against her forearms. She barely managed to hide them from Dia’s sight below or under her arms.  
  
Dia gasped. Her body stiffened.  
  
Stealing glances caught the memorizing view of Ruby’s breasts bounce and fall against each other. The brief glimpse of her cute nipples sent boiling electricity up her spine, and she lost herself in a jeer of wonderful over-stimulation.  
  
“I told you I want to see everything, so you don’t have to hide from me!” Dia half-scolded, half-praised Ruby, not knowing where she was on the scale anymore. Beside herself, she took a small step forward. Yes, all praise!  
  
“I-I know!” Ruby squeaked in alarm. Her stomach did a funny, eager somersault after she heard Dia’s tone change from patience to amazement. Her voice was rough, dripping with an unknown thrill.  
  
“Then don’t hide yourself,” Dia said.  
  
“I just didn’t know if they’re… I mean, I mean, I was thinking about this. When you were hugging me earlier. And we were k-k-kissing. Because I…” Ruby’s mind recalled Dia’s chest pressed down on hers. Her body had pushed her into her covers. Her chest had felt different compared to hers while they were close and inseparable, and she had wondered how Dia thought of the feeling. It was a pleasant feeling but also confusing. “I couldn’t help but notice that… It was good, and Onee-was… m-moaning... Okay, Onee-chan was happy then.”  
  
Dia examined Rub’s facial expressions change. Her deepest insecurities were well-known to Dia for the most part, but she was likely thinking too much about the details. It was better to leave that alone. She opened her arms and held them out. “Very, very happy, Ruby. And this – this, too! Come here, Ruby.”  
  
Ruby’s self-doubts crashed into her heart at once but chilled like ice freezing. Her sister beckoned her, and she couldn’t refuse the invitation. Her will to please Dia overshadowed the question of her breasts like a command; she wanted to leap forward and hug her head-on.  
  
Her arms tensed. Still, she made the sacrifice, and she was soon within Dia’s reach, bringing them close together.  
  
With each crisp step, those bountiful breasts squeezed even tighter under her arms. Ruby shivered. Goosebumps rose on her arms. Slowly, her confidence mounted in her steps. Her attention was nothing like performing live on stage and weaiting for the results. Pleasing Dia was twice — no, three times more! — as intimidating as the Love Live was!  
  
The sway of her body was unbearable for Dia. The top and bottom of her breasts peeked out from their hiding place, and she forced herself not to leap, her body’s anticipation and need driving her crazy. Dia barely contained the carnal urge to fondle them to her heart’s delight.  
  
All her pent up lustful feelings released once she was within reach of her.  
  
Dia’s hands dropped to the innermost of Ruby’s back, and Ruby vise-versa found purchase on Dia’s upper back near her shoulders. The firm, round curve of their breasts touched with a hint of hesitation, straightforward curiosity, and undeniable teases of each other’s near warmth.  
  
Dia sighed in amazement. She was… She couldn’t put her feelings into words.  
  
“Ruby, you’re amazing!” Dia said.  
  
Ruby, blushing, couldn’t take it anymore.  
  
“Let me ask this. And, um, um, um, I want to hear you tell me...” She peered down to their half-rubbing breasts. The gears in her brain whirled, her desire to hear her sister praise her more teetering higher and higher. “Am I, I… too big?”  
  
Her brain paused long enough to process this question. Truthfully, Dia could not believe her ears, the blood in her ears rushing almost angrily in protest. She was blessed Ruby had a well-endowed chest! Ruby’s breasts were blessed with busty curves and graceful slopes. Yet, she could ask her such a question?  
  
“Now, Ruby, that was what you were worried about? How silly,” she told her with upmost honesty. She smiled. She stroked her sister’s back gently. She shivered against her, the tops of her breasts bumping, sending a roar of need through Dia’s chest. “Having breasts ‘too big’ is impossible. Caring about showing off is not a concern a lady should entertain. Any size is wonderful.”  
  
The admission was helpful, yet Ruby had one last reservation. “B-But… Will…? When we put them together, won’t it be awkward. They’re totally different sizes?” Taking a breath, she composed herself. “I was worried… for _that._ If we would fit, or if it would be… I don’t know if we...”  
  
Ruby’s hand slid on her back and settled on her nape. It was silly, as Dia assured. But she had never been so conscious, outright thirsting for acceptance and the attention on her assets, until Dia’s body was flush against hers and demanded more. Her thoughts were jumbled. From the corner of her eye, Dia’s breasts were cute and small compared to hers.  
  
“Absolutely. That isn’t even a question!”  
  
Dia had quite enough of letting Ruby’s imagination run wild. The longer she worried, she would not feel the pleasure she had in store for her. And the hand on the base of her neck made her pull her closer with a no-nonsense push. Their bodies bounced skin-to-skin, heat-to-heat, and they slid into place.  
  
Truly, her sister’s generous bust had developed beautifully. She wished she could keep praising her in words—Ruby had believed her breasts would stay modest before she grew, and she had always fantasized of catching up with girls in racy idol fashion magazines and wearing tight bikinis—but Dia could not articulate proper words. She was far, far too gone, her body doing the work.  
  
Ruby’s back straightened. She gripped onto her shoulders for extra support. Her thoughts temporarily wiped clean of all thought, of indecision, of the need to impress Dia. Likewise, she would follow in her footsteps and match her. Not in size, but… Suddenly, size didn’t matter. Yes, they were one, just like this!  
  
Before her, her skin was so, so silky and just the right smoothness as her petite breasts. She must use the most sweet of creams. Ruby was almost hypnotized.  
  
Her mouth parted, questions forgotten, and her eyelashes fluttered in want.  
  
Their lips met. The kiss was long and deep and a little bit sloppy with the uneven movements of their chests. Ruby’s knees buckled under Dia’s hips bumping against hers. Their school skirts were still on, and the friction drove her desire on a higher level. Their breasts rubbed up against each other fully.  
  
Squirming, Dia angled to make herself comfortable. No, she couldn’t find an angle where Ruby’s larger breasts didn’t take up the room between them. She was charmed beyond belief; she loved how she stole the space and left no room for Dia to be left without her touch.  
  
“Oh,” Dia sighed, feeling strangely wild and off-kilter. Chasing her touch peaked her base desires. “I need more.”  
  
“Onee-chan, you really want more?” Ruby asked. She could feel each inch of her body from her upper chest to her stomach, and it was already like this… She was new to having their bodies rubbing. What else could they do?  
  
Dia shot a glare. “I do, absolutely! Never doubt yourself when it comes to this!” Internally, she fumed Ruby couldn’t see how much her charms turned her on. Soon, she would squeal with delight. Her lips partially opened, tongue sticking out while she panted. “Huge. They’re huge… Amazing, amazing!” She squashed the remaining space between their breasts together. “Press into me, Ruby. Your big sister loves your voluptuous body.”  
  
“Okay! O-Okay, I will!” Ruby said.  
  
Her groan tone caused her to sigh, but happiness bubbled up in her stomach. When she was serious and prideful of not only herself but Ruby’s motivation, well… Ruby’s blush brightened, but she didn’t have long to take note of her desire.  
  
Dia’s arms clumsily looped wider around her bare waist and crushed their chests together, tightly and roughly, so strongly their heartbeats erratically pounded against each other’s sweaty skin.  
  
Dia’s tongue swipes intensified on her lip. Ruby succumbed under her assault. The energy from their earlier make-out session came back to her, though she was still getting used to her technique. Biting back on her plump lower lip, she finally relaxed. Her tongue swirled lower around her mole and weakly flicked and sucked. She bucked harder on her torso, instinct only to interlock their breasts.  
  
Dia’s arched, her body limp. At first, she registered the hardened sensation on her breasts as the weight of Ruby’s breasts baring down on her with force. As time passed, she realized the small points jabbing into her flesh and working her into a frenzy were her bare nipples.  
  
If her breasts were heaven, the addition of her nipples sent her over the moon!  
  
At the same time, the pert nub of Dia’s left nipple glided on her skin and harshly poked her inner breast. Her right nipple slid against Ruby’s right areola and grazed her nipple. Flares of fresh need washed down both of their spines.  
  
Ruby’s mouth gaped, and she panted heavily. The kisses tipped her remaining consciousness into a near breaking point, and the sinking physical hardness of her nipples made her blood race. Arousal tingled in between her legs.  
  
Dia’s nipples hardened even more, painfully so, her body hurting with pleasure and the joy of physical contact. Her whole body vibrated as her nipples scraped and trailed lines down and up her breasts. Her breasts bounced as she tilted and crushed their chests.  
  
“It’s so good. So soft, Onee-chan,” Ruby gasped. Her back also arched, her head tilting backwards to get a better view of their breasts. Yes, her sister enjoyed her size, but she was still enamored with the intoxicating feeling of her skin on hers. Her breasts were pliable and perky, beyond the brink of her dreams.  
  
Her arms fell farther down her younger sister’s back, breasts cozily trapped. Dia heaved a muffled moan, rocking them even more intensely. The weave and slap of breasts each time they grinded and stretched and slammed into each other was too much to process. She stared her sister’s eyes, and she stared back, all but lost in drowning ecstasy.  
  
Ruby lost her balance and loosely held Dia from around the neck. Having an idea, she reached down, cupped the sides of her breasts, and smothered their breasts even harder upon each other.  
  
Dia dug her nails into her back. Her mouth opened in a silent scream.  
  
Needless to say, Ruby was satisfied her big sister couldn’t get enough of her. Moving away a little bit from one of their kisses, she grinned. Usually, she wasn’t that devious, but she wanted her plan to work – and oh, did her ploy work!  
  
Ruby’s plan worked so well on her that Dia’s change of mind was swift.  
  
The heat pooling in between Dia’s legs was off the charts. Mind drifting, she stepped backwards, pulling herself from their kiss as well. She gave into her impulses and, with a dip of her head, let her head dive into Ruby’s chest.  
  
She nuzzled her face in her cleavage. Her nose and chin plunged in the space separating her breasts. Inhaling her light and flowery scent, she was floored. She let her flesh press on her cheeks and envelop her in their world. Unable to resist, she licked one breast from the top to the bottom, then the other breast on the side, not knowing where to start.  
  
Ruby’s entire body seized up. Her soft tongue, her face… She gave her so much attention. Her breasts were enveloped with Dia’s tongue carelessly grazing her, and her eyes rolled back in her head.  
  
“That’s not fair!” Ruby cried. The feeling of Dia’s moist lips and burning cheeks on her breasts made her groan and hiss.  
  
“Completely fair,” Dia shot back.  
  
Ruby didn’t know how to respond to that. Instead, she shocked herself. She reached for Dia’s unattended nipples. With a firm grip, she took both hardened nipples in between her fingertips. She twisted them, stroking them, tweaking them to comply with her touches.  
  
Buried in Ruby’s breasts, Dia’s muffled moan increased with the arousal in her groin. Dia’s body flooded with elation; her hands were relentless. Ruby played with her nipples, rubbed them directly, and gave her too much stimulation.  
  
Where had her beloved sister learned to be so lewd and hands-on? Was her body just too willing to melt under her hands?  
  
“That’s not fair, Ruby,” Dia growled. Waves of arousal heightened each time she stroked and pinched her nipples.  
  
Ruby shook her head, unable to speak.  
  
Her instincts took over. Keeping her face planted in her breasts still, she yanked her backwards and stumbled towards her bed. Ruby groped onto Dia while she managed to pushed her backwards.  
  
The room spun around them. The soft covers of the bed hit Ruby’s back, and Dia’s body was above her once again.  
  
It was going to be a long night.


End file.
